The Protein Corona Effect for Targeted Drug Delivery

Currently, ligand binding to nanoparticle surface is the most widespread strategy for targeting specific tissues by a receptor-mediated mechanism. However, the nanoparticles are immediately covered by a rich protein layerwhen administrated in vivo, the so called “protein corona”, with the immediate consequence that the ligand-receptor recognition may be obscured. It is not the nanoparticle bulk composition or surface functionalization but rather the identity, arrangement and residence time of the proteins of the corona that determine the nanoparticle bio-identity and this is an emerging concept available for use to target specific cell types in a controlled manner.An in-depthunderstanding of the relationship between surface properties of nanoparticles and composition of the ‘protein corona’ is afundamental step towards the design of nanoparticles that, once in the blood, become covered byspecific proteins able to deliver them at the right site of action and promote efficient cell internalization. This “protein corona effect” is a formidable challenge that could lead to a complete renewal of the current strategies of targeted drug delivery.